The invention relates to an apparatus for a sliver-forming textile machine, especially a draw frame, flat card or the like.
In certain sliver-forming textile machines a fibre structure (fibre web) coming from the delivery rollers of a drafting system passes through a web guide and a sliver funnel with take-off rollers, the web guide has an inner wall (deflection and/or guide face, and a frictional resistance offered by the inner wall acts on the fibre structure.
In the case of a draw frame, the fibre web, which consists of a plurality of drawn fibre slivers, is delivered at high speed from the delivery rollers of the drafting system and is introduced into the entrance opening of the web guide. The fibre web meets the inner wall of the approximately funnel-shaped fleece guide, is condensed and diverted towards the exit opening. The exit opening is arranged downstream of a sliver funnel, through which the fibre material is drawn off in the form of a fibre sliver by take-off rollers.
In the case of a known apparatus (DE 26 23 400 A), the web guide is provided on its side facing the drafting rollers with a sliding-contact face of concave form. The width of the sliding-contact face is greater than its height. The maximum depth of the sliding-contact face is selected so that it does not exceed 1.5 times the fibre length, measured from the nip of the feed roller. The structural form of the web guide is fixed, especially in operation. The path on which the fibres move from the drafting system through the web guide changes. The fibres of the fibre web along the lateral edges of the approximately triangular web guide and the adjacent fibres have to cover a greater distance than the fibres in the middle of the web, which leads to mutual displacement of the fibres, which adversely affects their parallel position and hence the uniform nature of the fibre fleece; it is even possible for tears to form at the edges thereof, with the result that the fibre sliver often becomes rough and wavy. In addition, it is inconvenient that it is impossible to adapt the web guide to different operating conditions and fibre material qualities.
It is an aim of the invention to produce an apparatus of the kind described initially, which avoids or mitigates the said disadvantages and which in particular in a simple manner enables the web guidance and sliver quality to be improved and allows the web guide to be adapted to different technical parameters, such as fibre material properties, working speed and the like.